Apparatus for sealing containers



Dec. 16, 1941. R. E, LQWEY HAL 2,266,054

APPARATUS FOR SEALING CONTAINERS Filed Sept. 23, 1939 4 Shets-Sheet 1Dec. 16, 1941.

R. E'. LOWEY ET AL'. 2,266,054

APPARATUS FOR SEALING CONTAINERS Filed Sept. 25, 1939 4 Sheets-Sheet 2Dec. 16, 1941.

E. LOWEY ETAL APPARATUS FOR SEALING CONTAINERS Filed Sept. 23, 1939 4Sheets-Sheet 3 V Patented pee. 16, 1941 APPARATUS FOR SEALING CONTAINERSRoy E. Lowey, Cook County, and Edgerton A. Throckmorton, Kane County,111., assignors to Container Corporation oi America, Chicago, 111., acorporation 01' Delaware Application September 23, 1939, Serial No.296,236

- UNITED STATES "PATENT oFFioi: I

3 Claims.

The present invention relates to apparatus for sealing containers andmore particularly relates to the top sealing of tubular cartons havingoverlapping end flaps.

\ One object of the present invention is to provide a simple andeffective form of apparatus for sealing the flaps of a carton in aclosely associated manner whereby not only sifting or leakage of thecontents of the carton will be prevented but the carton will also besealed in a substantially gas tight and vapor proof manner.-

Another object is to provide an efiective appa- 'ratus for sealing theflaps of acarton whereby the flaps may be sealed in a closely relatedmanner irrespective of whether or not the contents of the cartoncompletely fill it and such sealing being effective without appreciablepermanent distortion or reshaping of the carton structure.

A further-object of the invention is to provide an economical andeificient apparatus for sealing the top closure flaps of a carton wherethe entire carton, including the top closure flaps, has been previouslycoated with a thermoplastic material.

A still further object of the invention is to pro-.

vide an improved apparatus for applying temporary localized pressureagainst the outside surface of the carton to be top sealed, in such away as to form an efiective support for the first flaps to be foldeddown into closing position so that the remaining flaps may be broughtdown over the first fiapsand then held for a sufiicient period to permitthe fiaps to properly adhere under the influence of a thermoplastic orother adhesive coating applied to the flaps.

A further object of the invention is to provide apparatus for contactingthe exterior walls of a carton to hold the closure flaps in properlyassembled position during drying ofthe adhesive on the flaps, in whichthe contacting means is caused to resiliently engage the proper pointson the carton walls and hold the-closure flaps in place withoutpermanently deforming the carton walls or scratching or otherwisemarring the exterior surfaces of such walls.

A still further object of the invention is to provide resilient cartonwall engaging devices of the type referred to above which are adjustableso as to permit the accommodation of varying sizes likelihood of thethermoplastic material sticking to the belt.

Other and more specific objects will appear as the description proceeds.

Inthe drawings:

Fig. 1 is a more or less schematic elevational view of a. machine forcarrying out the present invention;

Fig. 2 is a series of perspective views of the carton together withcertain fragmentary parts of apparatus, illustrating the sequence ofsteps through which the carton is carried to completely seal it;

Fig. 3 is an enlarged plan view of a portion of the apparatusillustrated in Fig. 1, such view being taken along line 3-3 of Fig. 4;

Fig. 4 is an enlarged side elevational view of the apparatus illustratedin Fig. 3, taken along line 4-4 of such latter figure;

Fig. 5 is a sectional view taken along line 5-5 of- Fig. 4, looking inthe direction of the arrows;

Fig. 6 is a fragmentary detail view showing a carton and'pressermechanism for exerting pres-,

sure upon the upper portions of the carton;

Fig. 7 is a fragmentary sectional view taken on line 1-1 of Fig. 6,looking in the direction of the arrows, illustrating, in a somewhatexaggerated manner the method of exerting temporary pressure on thecarton to keep the inner closure flaps in position against the lowersurface of one of the overlying closure flaps.

Fig. 8 is a view in elevation, certain parts being shown in section, ofa modified form of apparatus for exerting pressure on the upper portionsof the cartons to retain the downfolded underlying closure flaps inproper closure forming position; and

. Fig. 9 is a horizontal sectional view of the same flaps of regularlyformed folded cartons after I they have been filled with a desiredcommodity.

- A principal feature of the invention is to overcome certaindisadvantages that have existed in the machines heretofore employed dueto the fact that the usual narrow underlying flaps projecting from theedge or narrow walls of the carton are not properly secured to thebottom surface of the overlying flap or flaps, particularly when thecommodity introduced into the carton to be sealed does not completelyfill it. According to the present invention an apparatus is provided formore or less positively maintaining the underlying end wall underlyingfiaps against downward movement into the carton even though thecommodity packed in the carton is not suflicient to fill it entirely tothe top, this being done without permanently distorting or marring thecarton. 7

Referring more particularly to the drawings, there is disclosed afilling and sealing machine designated as a whole at II, which comprisesa suitable frame H, capable of being bolted to the floor or othersupporting surface. The frame ll comprises spaced frame elements l2, l2,arranged to support the various parts of the machine.

As disclosed herein, the cartons l3, I3, which have been previously setup and closed at one end by means not shown are placed on a suitableconveying means herein illustrated as an endless belt conveyor, and thecartons are carried by this conveying means to a filling station,generally indicated at I5, then past a station l6 for bending inwardlythe fiaps located on the end walls of the carton, then past a station l1for successively folding in the-wide flaps located on the side walls ofthe carton. The cartons are then moved so as to come in to engagementwith a side wall pressing means, indicated as a whole at l8 and, lastly,the cartons are moved into operative relation with a suitable device,indicated at IQ for applying and maintaining downward pressure upon theoverlapping top fiaps of the carton.

' As previously indicated the conveying element I4 is preferably in formof a suitable endless belt type of conveyor although other conventionalforms of conveying means could be employed with equal facility. In thepresent instance the conveyor belt 22, formed of canvas or otherflexible material, is supported at its ends on an idler roll 23 and adriven roll 24 suitably mounted on the frame II. For the sake ofsimplicity only the roll 26 is shown in detail.

Theroll 24 is suitably keyed to a drive shaft 25 which may be connectedto any suitable source of power, such as an electric motor. The driveshaft 25 is suitably journaled on the frame elements l2, 12. Asupporting plate 21, secured to the frame l2, I2, is provided forsupporting the belt 22 between the rolls 23 and 24.

The belt 22 is preferably provided with suitable cleats or spacingelements indicated at 28, 28, for properly registering the cartons onthe conveyor belt and guiding elements, indicated at 29, 29 formaintaining the cartons properly centered on the belt.

The cartons l3 are first set up and have the bottom flaps suitablysealed, as by means of ordinary glue or similar adhesive. They are thendeposited upon the conveyor by any conventional means, or by hand ifdesired. The conveying means l4 carries the carton to the fillingstation l5 which may be suitably controlled so as to automaticallydeposit a measured quantity of commodity into the carton.

The cartons may have the top flaps sealed by adhesive in the same manneras the bottom flaps. The present machine, however, is designedparticularly for handling cartons which have been submerged in a hotthermoplastic substance so as to apply a coating of such thermoplasticsubstance substantially uniformly over both inner and outer surfaces ofthe carton walls as well as the bottom and top closure flaps.

The cartons l3, l3, after having been sealed at the bottom, coated withthermoplastic, and

suitably filled, as previously stated, next pass to the station 16 wherea folding element 32, automatically controlled to operate in synchronismwith the movement of the carton on the conveyor by conventional meansnot shown, depresses the rear edge wall flap so as to cause it to assumea position substantially in the plane of the upper edges of the cartonwalls. The forwardly disposed edge wall flap 34 is depressed into asimilar position by means of a suitably formed shoe element 35 having acurved face 36. The side faces 31., 31, of the shoe 35 are arranged tocontact the inner surfaces of the side wall flaps 38 and 39 of thecarton. In the present instance the side faces 31, 31 are inclined toeach other in an upwardly diverging manner so as to cause firmer contactof the side wall flaps against such sides.

The shoe 35 is preferably heated by suitable electric heating units, notshown, so that when the flaps come in contact with the 51100. thethermoplastic coating thereon will be rendered soft and tacky.

After the carton passes out from beneath the shoe 35 it is acted on bythe parts of station 11 which includes two properly curved stationarycam elements 40 and 4|. The cam element 40 is arranged to engage anddownwardly fold the side flap 38 and the cam element 4| is arranged todownwardly fold the side flap 39. The cam elements 40 and 4| are securedin any suitable way as by bolting same to a portion of the frame, asindicated at 42.

As the cartons continue to pass along on the conveying means l4, theyare acted upon by the side wall pressing means l8 which will now bedescribed.

The side wall pressing means, as herein disclosed preferably comprises apair of endless' the sprocket 46, a bevel gear 52 is keyed to the so asto contact'the side walls of the carton" slightly below the place of theinner, downfolded, top closure fiaps 33 and 34, see Fig. '7. In thepresent instance the presser plates 51 are so designed and controlled asto engage only the central portion of the side walls, as best seen inFig. 6. It is to be understood that the driving gears for the chainelements 44, 45 are so designed as to move the chain in exactsynchronism with the movement of the belt 22 which carries the cartonand the links 56 are so placed as to contact the central portion of theside walls of the carton when properly held between the spacer members28, 28. For the purpose of supporting the inner run of the presserchains 44 aeeaoos and 45 there are provided guiding elements 66 and 59,in the form of vertically disposed plates against the surface of whichthe rear sides of the links. particularly the presser plates 51 on thelinks are adapted to engage. Inwardly directed parts 60 and 6| areprovided to serve as the downfolded flaps of the cartons will now bedescribed. Referring to Figs. 3, 4 and 5, this closure flap pressuremechanism comprises a belt 63 supported at one end over an idler roll 64and at the other end on a driven roll 65. For the purpose of driving theroll 65 the shaft 66 on which it is mounted carries a bevel gear 61which meshes with a bevel gear 68 on the shaft 49 carrying the drivensprocket 46.

The end of the belt 63 first coming into contact with the top of thecarton I3 is so designed as to begin to apply pressure to the tops ofthe cartons immediately after the presser plates 51 of the side wallpresser chains have come into play to slightly deflect inwardly the sidewalls of the carton. This relationship of parts is best illustrated inFigs. 3 and 4.

Means are preferably provided for maintaining a yieldingpressure on thetop of the closed cartons and for this purpose a plurality of elongatedopenings 69, 69 are provided in the vertically extending plates 58 andin these openings are received the spindle ends of a plurality ofrollers, indicated at III, III; As the cartons pass along beneath thetop presser belt 63, the weight of the belt and of the rollersimmediately above the carton will be imposed upon the downfolded andoverlapping fiaps. This weight will be of a yielding nature and thusprevent an undue amount of pressure from being exerted upon the top ofthe cartons.

For the purpose of preventing sticking of the hot thermoplastic coatingon the carton flaps to the top presser belt, the belt is preferably keptmoist by applying suitable quantities of water to it from time to timeasneeded.

The sequence of operation of the machine of the present invention uponcartons is clearly indicated in Fig. 2. The carton indicated at A, hasjust been filled and the closure flaps are still in an upstandingcondition. At 13, the end wall flaps are partially turned in due to theaction of the element 32 and the heating shoe 31. At 0, the heating shoe31 is shown in position in which heat is being applied to the flaps 33and 34 as well as to the inner faces of the flaps 38 and 39. At D theflap 38 has been folded substantially its lowermost position, the fiaps39 remaining in its origina1 standing position. At E, the side wallfiaps are shown insubstantially their final position. At F, the cartonis shown in a closed position and is just beginning its passage underthe downward pressure-applying belt 63.

When the completely sealed carton reaches the end of the machine it canbe removed by any conventional, well-known means or by hand.

The modified form of the invention illustrated in Figs. 8 and 9 differsfrom the form illustrated in Figs. 1 to 7, inclusive, in that thepressure means for applying deflecting pressure to the upper edges ofthe side walls of the cartons is provided by an oppositely disposed pairof endless pressure elements, such as' relatively narrow, flexiblebelts, it being unnecessary for this form of pressure mechanism to bedefinitely synchronized with the remainder of the sealing machine forthe reason that continuous pressing surfaces are provided. I

Referring particularly to Fig. 8, there is pro vided a base frame III,similar to frame H,

comprising spaced frame elements H2, H2 for supporting the operatingparts ofthe machine. The cartons I I3, identical with cartons I3, aresupported on a conveyor H4, designed to convey the cartons from thefilling'and closing stations,

not shown in this modified form, but which may be identical with similarparts in the form shown in Fig. 1. In addition to the belt conveyor H4the present modified form of the invention includes a side wall pressingmeans designated generally at H8 and a top pressing device indi- V oatedas a whole at H9.

The conveyor H4 is of the endless belt type having a belt designated atI22 supported at one end on a driven roll I24 and at its other end by asimilar roll not shown which can be an idler roll, as indicated at 23 inFig. 1. The roll I24 is keyed to a drive shaft I25 connected to a sourceof power, and suitably joumalled on the frame elements H2, H2. Asupporting plate I21, secured to frame I I2, I I2, supports the upperrun of belt I22.

As in the case of belt 22, the belt I22 is preferably, although notnecessarily, provided with spacing and guiding elements I28 and I29.

After the carton H3 is given a suitable adhesive treatment and the flapsclosed, as by means of the devices illustrated in Fig. 1, it is thendelivered to the side wall presser device H8 which will now be describedin detail. This 'device I I8 in this modified form of the inventionpreferably comprises two identical endless belt elements. I44 and I45.For simplicity only the element I44 will be described in detail.

The presser element I44 comprises essentially a belt I46 passing over asheave I41, so positioned as to bring the belt into contact with thecarton H3 at a point just below its upper edge as best seen in Fig. 8.For the purpose of driving the sheave I41 it is keyed to a verticalshaft I49 carriedby a bearing I56 which is in turn carried by arms I5I,projecting from one of the frame members H2. A bevel gear I52 is keyedto the shaft I43 and meshes with a bevel gear I53 keyedto the drivenshaft I25.

The belt I46 is preferably round in cross section and may be formed ofany suitable relatively flexible material such as rubber, leather orwoven cord.

The arrangement is such that when the closed cartons I I3 are brought inbetween the two belts I46, I46 initial light pressure will be applied tothe carton side walls at points substantially in line with the axes ofthe sheaves I41, I41.

Means are provided for applying a. somewhat increased pressure on thecarton side walls when the advancing edge of the carton'clears the arealying between the contours of the sheaves I41, I41. For this purposethere are-provided two opposing series of pressure applying rolls I55,I55 yieldingly mounted on the frame of the machine and bearing againstthe outer sides of the two belts I46, I46. In the present instance therolls I55 are secured in individual yokes I56. Each yoke being suitablyformed or secured on the end of a rod I51 slida'ble in a guide block I58which is exteriorly threaded so as to be adjustably associated withframe plate I59 provided with interiorly threaded openings. A suitablecoil spring I60 is provided bearing at one end against the yoke I56 andat the other end against the guide block I58 thus producing a thrust tothe yoke and forcing the roll I55 against the belt I46. The guide blockI58 is preferably provided with an end portion I6| which is hexagonal inshape so as to adapt it to be rotated by a wrench when it is desired toincrease or decrease the tension on the spring I60. In order to preventrotational movement of the yokes I56, each yoke is slidably fitted intoan opening 156a.

formed in the frame element II2.

It is thus seen that the belts I46, I46 will engage the side walls ofthe carton H3 and deflect such walls inwardly at points located justbelow the plane of the closing position of the inner closure fiaps toapply pressure on the edges of these flaps and retain them in positionto insure that they will properly adhere to the overlying closure flapsas explained in connection with the first illustrated form of theinvention. In the presently described form it is not necessary tooperate the side presser mechanism in synchronism with the remainder ofthe device which was done in. the first form so as to keep the pressermechanism from exerting pressure on the comers of the cartons whichwould tend to deform them permanently and render them unsightly. Thebelt I46 is arranged to be urged toward the cartons with such moderatepressure as to properly deflect the mid portions of the side wallsinwardly but at the same time not to be suflicient to cause any bendingor deformation of the cartons at their corners.

The mechanism 9 for applying downward pressure on the tops of thecartons comprises a belt I63 supported at its one end over a driven rollI65 and at its other end over a suitable idler roll not shown. The rollI65 is keyed to a shaft I66 carrying a bevel gear I61 meshing with abevel gear I68 on the shaft I49 which carries the sheave I41.

The belt I63 is so related to the remainder of the device that it willbegin to apply top pressure on the cartons immediately after the sidewalls of the carton have been fully deflected inwardly. For the purposeof applying top pressure a series of rollers, one of which is indicatedat I10, is provided having reduced spindle ends "I fitting withinvertically elongated openings in the frame of the machine similar to thearrangement described in connection with the first form of theinvention.

The roll I10, illustrated in Fig. 8, is the first roll of a series, andit will be understood that the remaining rolls arranged with this formof machine wil be dsitributed rearwardly of the belt I63, this being thedirection of its travel, similar to the arrangement illustrated in Figs;3 and 4. The first roll I10 is preferably located somewhat rearwardly ofthe first pair of oppositely disposed rolls I55 so that inwarddeflecting pressure will be exerted by the first pair of rolls I55 priorto the time of increased down pressure being exerted on the closures ofthe cartons.

Summarizing the advantages of this form of support to prevent them frombeing displaced downwardly due to the application of downward pressureupon the overlying closure flaps while the adhesive between theoverlapping flaps is in the process of becoming set.

The pressure exerted by the belts I46 on the carton side walls can bereadily varied by ad-' justing the guide blocks I6I. These guide blocksmay, of course, be adjusted independently of each other so that, ifdesired, the pressure exerted on the carton side walls may be eitherprogressively increased or decreased throughout substantially the lengthof the belt I46. If desired, the pressure exerted by the individualrolls I55 can be varied to produce at first a relatively light pressure,becoming progressively increased in intensity until the mid portion ofthe belt I46 is reached, and then the pressure can be so adjusted as tobecome progressively lighter for the remainder of the travel of thecarton in conjunction with the belts I46.

The inward deflection of the side walls produced by the side wallpresser devices has the additional advantage, particularly in the caseof packing frozen foods, of excluding a portion of the air contained inthe carton thus reducin oxidation effects. If the food productintroduced into the carton is to be frozen subsequent 1y to itsintroduction, as in the case of nonfiuent foods, such as broccoli andspinach, the inward deflection of the side walls just prior to finalsealing causes the exhaustion of a portion of the air within the cartonand, since the deflection of the side walls is maintained until aftersealing is complete, the walls will tend to stay in their inwardlydeflected condition due to the fact that invention, it is to beunderstood that the lateral the carton is hermetically sealed. Then,upon freezing of the contents, with consequent expansion thereof, thisexpansion will be readily permitted by the side walls which will thereontend to regain their original undeflected condition.

In the case of food products which have been previously frozen-and arein a more or less fluent condition, such as peas and shelled beans, theinward deflection of the side walls of the carton containing suchproducts will express a portion of the air contained in the carton andthe carton will be sealed in such partially exhausted condition. Thiswill have the effect of reducing the amount of oxygen contained withinthe carton and will correspondingly lessen the tendency of oxidationeifects within the carton. Since the pressure on the side walls isexerted adjacent their upper edges there will be produced little or nodisturbing effect upon the body of the food product within the carton.

From the foregoing it is apparent that the present invention provides asimple and effective means for maintaining the inner top closure fiapsin a position substantially in alignment with the plane of' the upperedges of the side and end walls whereby, upon subsequent pressure beingexerted and maintained, the overlying flaps will be fir'mly adhered tothe underlying flaps thus obtaining a seal of maximum efiiciency for thetop of the carton.

It is also to be understood that the present invention is not limited touse with cartons the tops of which have been coated with a thermoplasticmaterial as the invention is equally applicable to the sealing ofcartons by means of liquid adhesive, not thermoplastic in character andquite satisfactory for effectively securing the flaps in close contact,particularly in cases where no complete hermeticseal of the carton isrequired, this being in the case of cartons for retaining comminutedmaterials which have a tendency to sift and therefore require a tightseal to prevent such sifting; a

A particular advantage which the machine of the present inventionpresents when employed with cartons being coated with a thermoplasticmaterial is that when the thermoplastic coating material is subjected todisruptive action due to bending of the flaps into the closure position,the heating shoe will engage these areas where fracture is likely to ordoes develop and will replasticize the thermoplastic over these areas orlines whereby as soon as the flaps are brought to a lowered or closureforming position the thermoplastic will be caused or allowed to form acomplete film along these areas or lines when the thermoplastic cools.This advantage is not obtained in the case of liquid adhesives which arenot thermoplastic, as, in the ordinary case, the adhesive is not spreadon the flaps so as to cover the score lines between the flaps and sideand end walls of the carton and thus even if the carton is coated withthermoplastic material and liquid adhesive is employed-without theapplication of heat, there is likely to be some leaking'at the scorelines due to disruption of the thermoplastic fllm. along the score uponbending of the flaps along such lines.

- While the present description sets forth a preferred embodiment of theinvention, numerous changes may be made in the method and theconstruction without deviating from the spirit of the invention, and itis therefore desired that the present embodiment be considered in allrespects as illustrative and not restrictive, reference being bad to theappended claims rather than to the foregoing description to indicate thescope of the invention.

We claim: 1. In apparatus for sealing the top flaps of cartons havingtwo parallel side walls disposed on opposite sides thereof, theimprovement comprising, in combination, means for conveying said cartonsin upright position, a pair of flexible elements in position to contactthe upper edge p'ortions of said side walls of said cartons on saidconveying means, means for moving said flexible elements at the samerate and in the same direction as said conveying means, means forapplying pressure to the outer sides of said flexible elements to effecta slight inward deflection of the upper portions of said side walls,whereby downward movement of said top flaps past their normal closedposition when pressure is applied thereto is prevented, and means forapplying and maintaining pressure on the tops of said cartons duringmovement of said cartons by said conveying means.

2. In apparatus for sealing rectangular cartons having top closureflaps, the improvement comprising, in combination, means for conveyingsaid cartons in upright position with said top flaps provided withadhesive and in closed position, a pair of flexible belts arranged tocontact the upper edge portions of oppositely disposed side walls ofsaid cartons on said conveying means, means for moving said flexiblebelts at the same rate and in the same direction assaid conveying means,pressure-applying rolls urged by resilient means bearing against theouter sides of said belts to effect a slight inward deflection of theupper portions of said side walls, whereby said upper portions firmlyengage the edges of the lowermost of said top closure flaps to preventdownward movement thereof'when pressure is applied to-the tops of saidcartons, and means for applying and maintaining pressure on the tops ofsaid cartons during movement thereof until said adhesive has become set.

- resiliency of said resilient means.

ROY E. LOWEY. EDGERTON A. THROCKMORTON.

